Breaking of virus resistance in tomato associated with synergistic interaction between Tomato chlorosis virus and Tomato spotted wilt virus
E Garc¨ªa-Cano1, RO Resende2 and E Moriones1
1Laboratorio Virolog¨ªa Vegetal, Estaci¨®n Experimental "La Mayora", CSIC, M¨¢laga, Spain
2Dept. Biologia Celular, Universidade de Bras¨ªlia, CEP 70.910-970, Bras¨ªlia-DF, Brazil.
Correspondence: rresende@unb.br
Tomato (Lycopersicon esculentum) is severely affected by viral diseases such as those caused by geminiviruses, tospoviruses, or criniviruses, which can result in significantly yield losses. Moreover, multiple viral infections are frequent found in nature with unpredictable pathological consequences. In fact, mixed infections between viruses may result in synergisms or antagonisms and can cause novel disease symptoms that could compromise virus control. In this work we have studied the possible interactions between the crinivirus (genus Crinivirus, family Closteroviridae) Tomato chlorosis virus (ToCV), and the tospovirus (genus Tospovirus, family Bunyaviridae) Tomato spotted wilt virus (TSWV), both viruses widely spread in the world. A tomato cultivar susceptible to both viruses, and a cultivar resistant to TSWV based on the Sw-5 gene but susceptible to ToCV, were used for inoculations. Simultaneous or delayed inoculations were assayed. Symptoms expression and virus accumulation were monitored in plants. A dramatic synergism was observed between ToCV and TSWV in plants of the susceptible cultivar after the simultaneous inoculation of both viruses, leading to a rapid death of plants. However, this synergistic effect was not observed in delayed inoculations. Interestingly, results indicate that the presence of ToCV in Sw-5-resistant plants previous to TSWV inoculation result in TSWV-resistance breaking. Financial support: CAPES, CSIC, MECD, FINATEC.
